Search the data

Callao-B (Peru) Site History

History Summary

Reference Level

The data have been linked to tide staff zero by the contributors. However, further analysis of the data has lead to adjustments of the reference level in separate segments. The following adjustments were justified by reanalysis of the tide staff observation sheets and/or by comparisons of the analog data to analog-to-digital Leupold Stevens data performed by Mr. Henry Pittock of Oregon State University.

*adjustment determined by comparisons of the analog with SDR and ENC data

All adjustments above are uncertain to a few cm. Since January 1989, the reference levels of the ENC and SDR have been monitored by an automated reference level switch (for more information, contact the UH Sea Level Center).

Quality Assessment by the UH Sea Level Center

Comment

The earthquake of 3 October 1974 is associated with a sea level rise of about 10 cm followed by a period of resettlement. Dr. Klaus Wyrtki of the Univ. of Hawaii has prepared an unpublished report on the effects of this quake on the sea level signal.

For the period from 1987 to the present, the analog, ENC, and SDR series were analysed simulataneously and the data in the final archive are a composite based on the best data for each time period summarized as follows:

From 18 August to 30 November 1992, numerous short gaps have been interpolated using residuals and the predicted tides. The uncertainty of the daily values is about ±3 cm. The '#' below denotes ENC data gap filled with ANA data. A separate series Callao-A exists with data for 1950-1965. These data are of good quality. The series appear on different levels and information for linking them is not available.